Telephone system.



PATENTED FEB. 20, 1906.

V R. SHERER. TELEPHONE SYSTEM.

APPLICATION FILED OCT. 17,1904.

2 SHEETS-SHEET 1.

witnesses No. 813,830. PATENTED FEB. 20, 1906.

' R, SHERBR.

TELEPHONESYSTEM.

APPLICATION FILED OCT. 17.1904.

2 SEEETS-SHEET 2.

Gttoznugo UNITED STATES PATENT ornron.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Feb. 20, 190 6,

Application filed October 17, 1904; Serial No. 228,785.

and out at thewill of the party using the line.-

The object of the invention is to render impossible the objectionable h abit of eavesdropping, either accidental or intentional. With the usual selective call system this objectionable feature of the party-line is migitated as i the bell at the station to be called only is than'the one called and to prevent their be-L mg again placed in communication with the line until the first party has, rung off.

With these objects in view my invention consists of the novel features of construction and combination of parts hereinafter set forth, pointed out in the claims, and shown in the accompanying drawings, in which- Figure 1 is a diagrammatic plan'of my in vention, showing three telephones on a partyline. Fig. 2 is a perspective view of a bracket holding the toothed sliding bar, ar mature-levers, and magnets. Fig. 3 is a detail view, partly in section, of the generatorshaft. 4 is a detail perspective view of the conical inner end of the generator-shaft.

- and the contact-points separated by inward movement of the said conical end. Fig.5 1s a detail view showing the construction of the slotted bar through which the pawls carried by the armature-levers Work. Figs. 6,

7, and 8 are details of construction.

In the drawings, A and B represent the line-Wires of a metallic circuit, though it will beobvious that my device could be used in connection with a ground return, either A or B representing ground.

O, C, and C represent, respectively, telephone-transmitters, and D, D, and D ceivers, one at each station. At each station I arran e two parallel X-shaped platesE, the arms oi which are connected by rods E. In the bracket thus formed is carried the main device for throwing the various stationsinto and out of communication with each other. Carried by each bracket therefrom is a vertically-movable bar F, suitably insulated from. the bracket E and also from a contact-plate G, carried by an upper rod F The lower end of the bar F rests normally on a contactplate G, which, properly insulated, is carried barF has arranged longitudinally on it a conductor portion F, which may be in the form of a metal strip'if the bar F is of wood or a non-insulated portion integral with the bar it the bar is of metal, and on the portion F are formed a plurality of rack-teeth F The bar F also carries a contact-plate F which is in "permanent'contac't with the portion F, and may, if desired, be integral with it, and which is adapted by means of vertical movement of the bar to be brought into contact -,with the plate G. While the bars F are all of identical construction, the location on the bar of the contact-plates F with reference to the teeth F varies and there may be as many positions of the plates F as there are teeth on the bars and as many telephones on the p artyline as teeth, each station having a bar F with a contact-plate Win a dili'erent position from any other plate F carried by a bar on that line. The bracket E also carries an-electomagnet H, having at one end a diamagnetic guard H, and an armature-lever H of soft iron is pivotally mounted intermediate its ends and is adapted to be drawn toward the upper end of the electromagnet H when the latter is energized and to be held from coming into actual contact with the magnetic pole by the guard H. The opposite and heavier end of the armature-lever H has pivoted to it a pawl H, adapted to engage the teeth F and lift the bar The bracket E also carries an arm E; to which is pivoted a pawl J, adapted to cugage the teeth F? and hold the bar F into the position to which it was moved by theiaction of the pawl'Hf. Asteel arr-naturedever J is pivoted intermediate its ends,'and the heavier end is adapted to engage the lower poleiace of the electromagnet H when the mag- 'by a supplemental bracket or'arm E". The

net is energized. the oppositerand lighter end is pivoted a vertical bar a lotted,- as shown atJ, .and the .pawls H nd J work through these slots, respectively, with a limited vertical mo'yement sufficient'in'its' scope to accomplish. the purpose for which they are designed.

It will be understood thatzthe-bracket. E

' and parts connected thereto may be arranged at any suitable place and either adacent to orremote from the transmitter and receiver. I o

Asuitahle generator-bell (not shown) of any desired make is arranged as usual in the telephonebox or casing. The armature-shaft of thisv generator is rotated in the usual .manner' bya gear-train, and in the drawings 1 show the ear-shaft K, having at its-outer end a cran handleKfthe shaft being formed in ,sections, as will be hereinafter explained, and

' carrying a gear-wheel K which meshes with I understood that the generator and bell' are the gear-Wheel (not shown) driving the are mature-shaft of the generator. It will be not-claimed as a part of this invention; but

' the gear-shaft K is an essential feature of my devi-ce; The inner end of the generator-gear sh'aft K is in the form of a truncated coneK.

The shaft K has a sleeve L pinned to the shaft,

the pin L extending through a longitudinal slot L' foim ed in the sleeve, so that the sleeve L will have a limited longitudinal movement on the shaft K. As previously stated, the

shaft. K is formed in-two sections, thecone tion carrying the cone is moved rearwardly,

sliding in the sleeve, the pin L and slot L -permitting this movement, while the inner and outer sections rotate with the sleeve as one common shaft. spring M is carried by the sleeve L and is wound upon the sleeve;

when the sleeve is rotated'by reason of turning of the handle K, but as soon as the hen:

die is released the spring rotates'the sleeve and sections of the shaft in the opposite direction and the parts are returned to their-(nor mal positions. The truncated cone'portion K is formed or covered with some suitable insulating material, and below the same is arranged an insulated bracket N, which carries an upwardly-extendin spring. member N, arranged on one side ointhe cone K and curving over the same. A similar spring N posite end- 'to the pin of the block 0.

cord is without the sleeve L and is notdrawn. taut; A ball 0 is arranged on the cord in:-

both springs making contact with the commutator-shaft S hereinafter mentioned, is ar ranged upon the opposite side of the cone K and these springs are adapted to enga e opposite faces of a contact-plate Ni t will now be obvious that as the members N and v N are arranged on opposite sides ofthe cone K and are of elastic material'that rearward dle K will force the cone farther between the said members and spring them apart,

' breaking contact with the plate N at the call" ing-station onlyv I The-outer end of the inner section of the shaft K carries a projection O, and. in the sleeve L a block 0". is slidably arranged, having a pin projecting through aslot, 'inthe sleeve, and a'cord O is connected at one end to the inner end of the sleeve L andat its optermediate its ends and-acts as a governor,

movem'ent of thecone on rotation of the Iran? 4 This i idrawi g the block 0 into enga ement with the projection 0, when the handle is rotated with sufficient speed to ain thereq'uired frequency of alternations 0 current,

A lever Q is pivoted intermediate its ends adjacent the bar F, and one end of the lever is connected to the lower end of the bar,'and' the opposite end of the lever is connected by a cord or wire Qto a weight Q which Weight is arranged in the casingcontaining the generrater-shaft K and to the rear of'th'e cone por- 'tion K -'As soon as the-bar F is 'moved up one step the weight Q? is dropped to the rear rod of the, cone K and it is thenimpossible to force thevcone rearwardly between the members N and N andthe cord or wire Q is mclosed in the casing or run through a suitable tube or pipe when the bar F is not adj acent, the generator, so that the weight Q cannot be lifted except by\the lowering of the bar F,

and it may be here stated that the bar F and bracket .13, may be incased in any suitable manner. I also employ a reversing-switch which may be of any desired form, but is shown as a slidable bar P, having the contact blocks P, .1 and P insulated from each otherand adapted to contact with the stationary contact-blocks P and P 'i The circuits connecting these various parts I are as follows: From the line Wire A a lead wire 1 runs directly to the receiver, and, alead-wire 11 has a branch 2, which'is con-i, 'nected to all "upper guide-bracket F through which the bar F works, the circuit being formed through the upper bracketF v and the conductor portion F of the bar F. The wire 11 has also a branch wire 3, which extends to the electromagnet H, and from the magnet extends a wire 4 to the contact plate or surface N The wire 1 has a tap 5 to the block it.- From the'block P awire' 6 extends to cone K 'away from the contact-blocks? and P wire extends to the For convenience of descri tion I have desig nated thestations as X,

' The/operation of. the parts is as follows:

' N, and wire 10 forms As soon as the bars plate F out of contact leads from the wire'o to the transmitter.

,description.

'Ys number being a tap 7 extend- A- branch wire 8 A extends to'a suitthe eontact plate;i and has mg to the contact-plate G wire 12 taps the wire 9 and ablecontact-plate R, adapted to be engaged when forced by the by the spring member N member N The interior circuits of the telephone proper are the same as usual and require no A ire 9 forms a connectingjoop between and and Z.

Assumin that station X-desires to cut out station and communicate with station Z, 2 and Z s being station 3, the handle K is rotated and three .rings sounded arid 'three successive impulses of currentare generated and each time the cone is forced between the members N and N breaking circuitbetween wires 4 and.10. The generator-commutator is indicated at S and and from the generator. Each impulse of the current will leave the stationX through wire 12, with which N is in contact, wire 9, blocks P and P", wires 6 and 7, contact plate G, the conductor portion F of the bar F, bracket F and wires 2 and 11 to wire B, and return throughwire 1,"tap 5, blocks P and P and wire 10 to the generator. It will be noted that thereceiyer and transmitter are looped in series each other and in parallel between the circuit-wires 1 and 6 as the circuit is above outlined through the tap 5. At the other stations received through the jollowing circuit: through wires 11 3, electromagnet H, wire 4, member-N wire 10, blocks P and P and back through wire 1. This will energize the magnet H, and at each lever H will be drawn downward, actuating the pawl H, which will engage the teeth of the bar F at each of the stations Y and Z, and the barwill be lifted one stepv for each ring. F have been lifted one step the weights Q? descend, and the generator ear shafts K of these stations are practica y locked against rotation, since rotation "necessitates an inward movement of the shaft-sections.

talking-circuit is therefore formed between while station Y is cut out, as it will be obvious that the bar F is lifted out of contact with plate Gr and withdts with plate G. The talking-circuit at stationX is formed through stations, X and Z,

om block P a. pring member N the circuit leading tothe impulses will be impulse the armatureinto 7 and resting on the said plate,

Wires 8 6 7, contact-plates G F F, wires 2 6 and 11 toline, and wire 1 pending on the direction of the current. The same circuit is formed at station Z, substituting contact-plates F and G for G. The magnets H of stations Y and Z remain in a circuit, wires 11 3 4, member N wires 10 an 1 through blocks P and P When the party at station'X is through, the reversing-switc 'P is moved, reversing the direction of the current in the usual manner, and the sudden reversal of the current causes an instantaneous motion on the part of the armature-lever J L which is conveyed to the slotted bar J and disengages the pawl J, and as soon. as the current is cut off the bars F at stations Y and Z fall by gravity and all parts resume their normal positions. 7

Having thus fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is- I 1. In a selective telephone system, the combination with a generator-gear shaft, a movable bar having a contact-plate, means for moving the-bar step by ste and means connected to the bar adapte to lock the said shaft when the bar has moved one step.

2. A selective telephone system comprising talking and ringing circuits, a plurality of movable bars having contact-plates arrange in the talking-circuit, a plurality of electromagnets arranged in the ringing circuit, pawls actuated by said magnets adapted to lift the bars step by step, and means for cutting out the electromagn'et at the calling-station.

3. A selective telephone system comprising talking -an/d ringing circuits, a plurality of movable, toothed bars having contact-plates arranged in the talking-circuits, electromagnets arranged in the ringing-circuits, a callbell generator, pawls adapted to engage the bar-teeth and actuated by the magnets, means for automatically cutting out the magnet at the calling-station, and means for locking the call-bell-generator shafts upon movement of the bars.

to or from line, de-

4. In a selective telephone system, a mov able toothed bar, a contact upon which the bar normally rests, a contact-plate carried by the bar, a contactplate arranged ad] acent the bar adapted to be engaged by the contact plate onthe bar, the saidbar forming a portion of the talkingcircuit, an electromagnet' in the calling-circuit, pivoted armature-levers, pawls actuatedby said levers and adapted to lift the bar step by step, and means for automatically-cutting the said magnet out of its own calling-circuit.

5. In a telephone system, a contact-plate, a

movable bar arranged an electromagnet, a generator-gear shaft adapted to-move inwardwhen rotated in one direction, and

in the talking-circuit.

having an insulated conical rear end portion, shaft and prevent inward move'nimnt of tnu spring members arranged on opposite sides same when the bar is lifted, as and For the [0 of said conical end and when in contact compurpose set forth. plating the circuit through the electr0magnet,'

pawls actuated by the magnet adapted to lift the bar, and a weight connected to the Witnesaes:

bar and adapted to be brought intb aline- JACOB H. SHERER, ment with the rear end of the generator-gear R UBY EMIAGILL.

RALPH smsmm 

